The present invention relates generally to speaker systems for use with computer systems and, more particularly, to a woofer/subwoofer speaker apparatus contained within a computer housing. More particularly still, the present invention relates to a speaker assembly that, during manufacture, is quickly and easily placed within a computer housing, that occupies a limited volume and that is universally designed so as to be adaptable in various orientations.
Audio speaker systems are well known in the art. Speaker systems have evolved from a single monaural speaker to multiple speakers that produce stereo sound that is more realistic sounding to the typical listener. Each speaker unit in a stereo speaker system typically comprises a plurality of speaker drivers within a single enclosure. The speaker unit typically uses two to three speakers, or more, with one speaker reproducing upper frequencies and another speaker reproducing lower frequencies. A third speaker sometimes is added to reproduce the lowest frequencies desired.
Recently, however, the trend has been to utilize multiple channels, which has led to using separate enclosures for each speaker. This allows the speaker system to have smaller components with the ability to place the speakers in discrete locations otherwise not possible with the larger enclosures typically used in previous speaker designs. Additionally, the woofer/subwoofer unit in the satellite speaker systems typically only produces a monaural tone as well and thus a second, matching stereo speaker is not necessary. With this in mind, speaker designers have attempted to optimize the acoustics reproduction of small enclosed subwoofer designs in order to save on space or to locate this speaker unit in less conspicuous locations.
Another advance in subwoofer speaker design that has decreased the overall unit size is the utilization of ported chambers. The ported chambers also enhance the sound quality of the speaker system, as well as increase the speaker""s responsiveness without adding to, or in some instances by even minimizing, the inherent distortion of the speaker. One design for a ported speaker system is shown in U.S. Pat. No. 5,623,132 issued Apr. 22, 1997, entitled xe2x80x9cModule Port Tuning Kit.xe2x80x9d This reference discloses the concept of adding a modular port to a speaker enclosure to enhance the responsiveness and accuracy of the speaker itself. A more complicated enclosure system is disclosed in U.S. Pat. No. 5,147,986, issued Sep. 15, 1992, entitled xe2x80x9cSubwoofer Speaker System.xe2x80x9d This patent discloses a subwoofer system that divides the enclosure into at least three chambers. Each chamber is tuned and acoustically coupled, one to another, so as to optimize speaker responsiveness while minimizing the enclosure volume. Both of these patents disclose what would be excellent speaker designs for designing and implementing a subwoofer speaker assembly that stands alone.
The use of speaker systems has expanded from that of reproducing sound in a stereo system to reproducing a rich, sonorous environment of surround sound in multi-media systems that include video replay in television and personal computer systems. It is in the computer multi-media system that conventional speaker systems such as disclosed in the above-referenced patents, although useful, have several drawbacks. For one, both such speaker systems still require a separate enclosure that occupies a certain amount of space. In a multi-media computer system, one must include not only the CPU box of the computer system, but also the monitor, keyboard, pointing device, printer, and any auxiliary peripheral devices that take up valuable desk or floor real estate either at home or in the office. Adding multi-media capabilities to the computer system requires sound to be reproduced and, to reproduce stereo sound, at least two speakers are required, for a right and left channel. Early personal computer systems included a monaural single speaker that was mounted within the computer system and only provided amusing beeps and tones, but never could duplicate stereo sound or full, rich audio sound currently desired by today""s users.
Accordingly, the same type of satellite speaker systems that have been used in both audio hi-fidelity systems and video systems with audio hi-fidelity have made their way to the market of personal computers. These include a right channel speaker, left channel speaker, and a monaural subwoofer unit. This requires three new components to be placed on the already crowded desktop of the computer user. Some users have gone to free up desk space by placing the CPU box on the floor or in another out-of-the-way location. Such an approach is helpful in that additional desktop space is then available. Further, the user can place the subwoofer anywhere close, without it having to be optimally positioned as is required by the right or left speaker. This is because the subwoofer does not produce stereophonic sound, but merely enhances the audio experience by providing the lower frequencies. It is -well known to speaker design engineers that a single subwoofer system is more than adequate for reproducing the low frequency end of the audio spectrum needed for full audio reproduction.
Placing the CPU box under the desk or moving it away from the desktop, as well as moving the subwoofer system off the desktop and in an inconspicuous place, are good approaches to provide additional desktop real estate. Unfortunately, they create additional clutter either under the desk or in the separate storage area where the two units must be provided. Additionally, in shipping systems with -multiple speaker sets, a larger shipping box is necessary to accommodate the typically much-larger subwoofer assembly than the two satellite speakers. This, in turn, incurs additional shipping costs as well as packing costs in terms of material and labor and time delays experienced in packing the unit.
Thus, what is needed is a satellite speaker system that overcomes the storage problems of the prior art by placing a subwoofer somewhere useful to the-end user, and without taking up unnecessary space otherwise required by the user. This advantage would also overcome and reduce the costs of packing, shipping, and handling of an entire multi-media computer system. Further, such a subwoofer configuration should have the same acoustic benefits that ported subwoofer designs offer.
According to the present invention, an internal subwoofer apparatus is provided that is placed within the central processing unit (CPU) box of a computer system. The computer system may be a multi-media personal computer system that is capable of providing visual and audio recording and playback. The CPU box typically includes the motherboard that houses the main central processing unit as well as any ancillary processing chips needed for the computer system. The CPU box may also include memory modules such as short term random access memory, long term disk storage memory in the form of hard disk drives or removable floppy disk drive systems, as well as long term hard disk storage units such as CD-ROM systems. User input to the computer system may be provided by a keyboard and, optionally, a pointing device, such as a mouse or track ball. A monitor that displays video signals viewable by the user may be provided and be connected to the CPU and driven by either the main central processing unit or by a separate video processor, such as a video card. An audio system may be provided that includes a pair of satellite speakers serving as a first channel and a second channel, typically known as the right and left channels, and further includes a subwoofer unit located in the CPU box. The CPU box can be oriented in a tower configuration or a desktop configuration.
The subwoofer unit is mounted in a lower front portion of the box, if it is a tower box, or in a front side portion, if it is a desktop box. The subwoofer is ported to enhance audio reproduction and to conserve space. The speaker may be mounted in a down-fire position, meaning that the front of the speaker is mounted downwardly against a vibration and sound absorbing mat, while the reflecting sound echos within the chamber and then is enhanced through the port that opens to the front of the computer system. A separate volume control and on/off switch can be provided on the exterior of the CPU so as to either activate or deactivate the subwoofer within the CPU box. The switch and the subwoofer are coupled to the motherboard or, alternatively, to an audio sound card installed within a computer system.